Very long delay in responding to volume keys and Ctrl+Alt+T

The keyboard sound funcitions aren't working when I try to use it, but a few minutes later, sometimes 5 minutes... sometimes 20 min; starts to work, turning the velumes up or down, mute on or off.
I just realised that the other keyboard commands are working too much late after I use them, simple commands like Ctrl+Alt+T (for the terminal) etc.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: pulseaudio 1:10.0-2ubuntu3
ProcVersionSignature: Ubuntu 4.13.0-32.35-generic 4.13.13
Uname: Linux 4.13.0-32-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.7
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC0D0p: djeant 2000 F...m pulseaudio
 /dev/snd/controlC0: djeant 2000 F.... pulseaudio
Date: Tue Jan 30 13:50:54 2018
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
InstallationDate: Installed on 2018-01-29 (0 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
ProcEnviron:
 LANGUAGE=pt_BR:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=pt_BR.UTF-8
 SHELL=/bin/bash
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
 No PulseAudio daemon running, or not running as session daemon.
SourcePackage: pulseaudio
Symptom: audio
UpgradeStatus: Upgraded to artful on 2018-01-30 (0 days ago)
dmi.bios.date: 01/06/2017
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.2.1
dmi.board.name: 07F37C
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 3
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.2.1:bd01/06/2017:svnDellInc.:pnInspiron3268:pvr:rvnDellInc.:rn07F37C:rvrA00:cvnDellInc.:ct3:cvr:
dmi.product.family: Inspiron
dmi.product.name: Inspiron 3268
dmi.sys.vendor: Dell Inc.